Intranight optical variability of low-mass active galactic nuclei: a pointer to blazar-like activity

Oct 11, 2022
Published in:
  • Mon.Not.Roy.Astron.Soc. 518 (2022) 1, L13-L18
  • Published: Nov 22, 2022
e-Print:

Citations per year

20222023202402
Abstract: (Oxford University Press)
This study aims to characterize, for the first time, intranight optical variability (INOV) of low-mass active galactic nuclei (LMAGNs) which host a black hole (BH) of mass ∼ 10^6M_⊙, i.e. even less massive than the Galactic centre BH Sgr A* and 2–3 orders of magnitude below the supermassive black holes (SMBHs, MBH∼108−109M⊙⁠), which are believed to power quasars. Thus, LMAGNs are a crucial subclass of AGNs filling the wide gap between SMBH and stellar-mass BHs of Galactic X-ray binaries. We have carried out a 36-session campaign of intranight optical monitoring of a well-defined, representative sample of 12 LMAGNs already detected in X-ray and radio bands. This set of LMAGNs is found to exhibit INOV at a level statistically comparable to that observed for blazars (M_BH ≳ 10^8–9M_⊙) and for the γ-ray-detected Narrow-line Seyfert1 galaxies (M_BH ∼ 10^7M_⊙) which, too, are believed to have relativistic jets. This indicates that the blazar-level activity can even be sustained by central engines with BHs near the upper limit for intermediate-mass BHs (⁠MBH∼103−106M⊙⁠).
Note:
  • Accepted for publication in MNRAS Letters
  • galaxies: active
  • galaxies: jets
  • galaxies: photometry
  • quasars: general